1. Field of the Invention
The present invention relates to the field of directory services. In particular, the present invention is directed to application of X.500, LDAP and similar services to a relational database, a database design and use of the database to perform X.500 services.
One aspect of the invention relates to the use of metadata, wherein different types of objects are stored together in the same table and in a generic way, in a directory service system and its method of operation.
Other aspects of the present disclosure are directed to an implementation using a RDBMS (Relational Database Management System). The present invention also comprises a property-based table structure and methods of operation of a database application.
2. Description of the Related Art
X.500 is the International Standard for Electronic Directories [CCITT89] or [ITU93]. These standards define the services, protocols and information model of a very flexible and general purpose directory. X.500 is applicable to information systems where the data is fairly static (e.g. telephone directory) but may need to be distributed (e.g. across organisations or countries), extensible (e.g. store names, addresses, job titles, devices etc.), object oriented (i.e. to enforce rules on the data) and/or accessed remotely.
Relational Database Management System
(RDBMS) provide facilities for applications to store and manipulate data. Amongst the many features that they offer are data integrity, consistency, concurrency, indexing mechanisms, query optimisation, recovery, roll-back, security. They also provide many tools for performance tuning, import/export, backup, auditing and application development.
RDBMS are the preferred choice of most large scale managers of data. They are readily available and known to be reliable and contain many useful management tools. There is a large base of RDBMS installations and therefore a large amount of existing expertise and investment in people and procedures to run these systems, and so data managers are looking to use this when acquiring new systems. Most relational database products support the industry standard SQL (Structured Query Language).
There has also been a move towards Object Oriented systems which provide data extensibility and the ability to handle arbitrarily complex data items. In addition, many corporations and government departments have large numbers of database applications which are not interconnected. Data managers are looking for solutions which enable them to integrate their data, and to simplify the management of that data. X.500 and it's associated standards provide a framework and a degree of functionality that enables this to be achieved. The fact that X.500 is an international standard means that data connectivity can be achieved across corporations and between different countries.
The problem, therefore, is to address the need of data managers and implement X.500 with all the flexibility of object-oriented systems but using an SQL product so that it can achieve the scalability and performance inherent in relational systems coupled with the stability, robustness, portability and cost-effectiveness of current SQL products.
There have been a number of attempts of solving the above problem and over a considerable period of time. None of the attempts have resulted in a product which has proven to be commercially accepted by the market, and thus in the market place there is a long felt need yet to be addressed.
FIG. 1 shows an abstract from the “GOSIPNews” issue No. 4, dated April 1994 (Source: “Interoperability Products” distributed in Australia by the Centre for Open Systems) and which lists X.500 products currently available. None of these products use a SQL database as an underlying data store, and none of these products therefore address successfully the market need of implementing X.500 using an SQL RDBMS.
The Proceedings of IFIP WG6.6 International Symposium (ISBN: 0444 889 167) have published a paper presented by Francois Perruchond, Cuno Lanz, and Bernard Plattner and entitled “A Relational Data Base Design for an X.500 Directory System Agent”. The Directory System disclosed, as with many prior art systems, is relatively slow in operation, particularly where the database is relatively extensive and is incomplete in its implementation of X.500, such as aliases, subsearch and entry information.
Another attempt is disclosed in the proceedings of IREE, ISBN 0909 394 253, proceedings Apr. 22-24, 1991 by C. M. R. Leung. In that disclosure, there is described a database scheme in which a single entry table holds detailed information about each directory object, and is also incomplete in its implementation of X.500.
This approach has been discredited by a number of text books and knowledge in the art, such as “Object-Oriented Modeling and Design” by J. Rumbaugh, et al, 1991, ISBN 0-13-630054-5, in which at paragraph 17.3.8 it is clearly stated that “putting all entities in the one table is not a good approach to relational database design”.
As noted above, there have been a number of attempts made to address prior art problems, but none of the attempts have resulted in a product which has proven to be commercially accepted by the market. Of interest in this application, are the solutions of problems that are associated with indexing, extensibility and scalability.